2015年职称英语理工类B级完形填空专项练习(4)

　　A dramatic and surprising magnetic effect of light discovered by University of Michigan1 researchers could lead to solar power without traditional semiconductor-based solar cells.

　　The researchers found a way to make an optical 1 , said Stephen Rand, a professor in the departments of Electrical Engineering and Computer Science, Physics and Applied Physics.

　　Light has electric and magnetic components. Until now, scientists thought the 2 of the magnetic field were so weak that they could be ignored. What Rand and his colleagues found is that at the right intensity, when light is traveling through a material that does not conduct electricity, the light field can generate magnetic effects that are 100 million times stronger than 3 expected. 4 these circumstances, the magnetic effects develop strength equivalent to a strong electric effect.

　　This could lead to a new kind of solar cell without semiconductors and without absorption to produce charge separation， Rand said. In solar cells， the 5 goes into a material， gets absorbed and creates heat. Here， we expect to have a very low heat load2. Instead of the light being absorbed， energy is stored in the magnetic moment3. Intense magnetization can be induced by intense light and then it is ultimately capable of providing a capacitive power 6.What makes this possible is a previously undetected brand of optical rectification4， says William Fisher， a doctoral student5 in applied physics. In traditional optical rectification， lights electric field causes a charge separation， or a pulling 7 of the positive and negative charges6 in a material. This sets up a voltage， similar to 8 in a battery.

　　Rand and Fisher found that under the right circumstances and in right types of materials， the lights magnetic field can also create optical rectification. The light must be shone through7 a 9 that does not 10 electricity， such as glass. And it must be focused to an intensity of 10 million watts per square centimeter 8. Sunlight isnt this intense on its own， but new materials are being sought that would work at lower intensities， Fisher said.

　　In our most recent paper, we show that incoherent light9 like sunlight is theoretically almost as. 11 in producing charge separation as laser light is, Fisher said.

　　This new 12 could make solar power cheaper， the researchers say. They predict that with improved materials they could achieve 10 percent efficiency in 13 solar power to useable energy. Thats equivalent to todays commercial-grade solar cells.

　　To manufacture 14 solar cells， you have to do extensive semiconductor processing， Fisher said. All we would need are lenses to focus the light and a fiber to guide it. Glass works for 15 . Its already made in bulk10， and it doesnt require as much processing. Transparent ceramics might be even better.

　　词汇：

　　optical adj.光学的

　　incoherent adj.非相干的

　　capacitive adj. 电容的

　　semiconductor n.半导体

　　rectification n.改正，修正

　　ceramics n.陶瓷

　　注释：

　　1.University of Michigan：密歇根大学。建校于1817 年，是美国名列前茅的公立大学，拥有优良的师资和顶尖的商学院、法学院、医学院和工学院。

　　2. heat load：热负荷

　　3. magnetic moment：磁矩

　　4. optical rectification：光学校正

　　5. doctoral student：博士生

　　6. positive and negative charges：正电荷与负电荷

　　7. shone through：shone是shine的过去式。shine through是通过.

　　8. an intensity of 10 million watts per square centimeter：每平方厘米一千万瓦特的强度

　　9. incoherent light：非相干光

　　10.Its already made in bulk：它已大量生产。in bulk 是大量，成批